A Study in Deduction
by mischievousanomaly
Summary: Sherlock Holmes is presented with a new case. A case that is so uniquely special that it poses a challenge which Sherlock has never seen before. A case that could change the world. A case that Sherlock never expected to face. But then... who would expect a case like this?
1. Chapter 1

Sherlock blinked, his eyes taking in the lazy dance of dust particles through the air. The sound of the water tank filling meant that John had to be awake already and would likely be leaving for work soon. Not that Sherlock minded. With no case, the day was bound to be so boring that the wall would pay the price for a lack of criminal activity. The wall would have it coming. He climbed up out of the bed and headed to the kitchen. Click. The kettle was on and boiling. Sherlock threw himself onto the sofa before disappearing into his mind palace.

"We're out of milk," John stated simply from the kitchen. From the kitchen? The sound of the water tank still echoed through the flat. There was someone else there. Not Mrs Hudson. The hoover could clearly be heard.  
"Yes," Sherlock agreed absentmindedly, surfacing from his thoughts just enough to reply, before diving back into his mind palace. There was a loud click as the door to the bathroom opened, and a young woman emerged.

She was dressed in a pair of black trousers and blazer, with a deep purple shirt. Her slightly damp curly, black hair had settled around her shoulders like a pool of ink. She was pale, clearly not having been on holiday recently, and her frail stature was suggestive of some sort of eating disorder. Clearly, she worked in some sort of office, judging by the choice of clothing and the hair tie around her wrist. Perhaps some sort of engineer or scientist. No tie suggested that they were used to picking clothing that wouldn't get caught in machinery…

"Sherlock?" John said. Sherlock jolted out of his mind palace. A client perhaps? Hopeful, he voiced his thoughts.  
"Client?" he asked. Perhaps he would have a case today after all. At the same moment, a female voice said "Yes?" Sherlock looked towards the source of the voice. "If you're clients, then you'll be disappointed to find that my interest is currently directed elsewhere. Your case wouldn't be anywhere above a three at most. As you've broken into my flat, you should be able to find your own way out."

"Your flat?" Sherlock said incredulously. Whoever this was, their case had already peaked his interest to an extent. "I believe that you are the one trespassing. This is my flat."  
"You don't seem to be lying," the female replied, a hint of intrigue in her tone of voice. Of course, he wasn't lying. "But this is my flat," she stated.  
"Perhaps you lived here before us?" John suggested. "Temporary amnesia perhaps? I'm John by the way."  
"And I'm Sherlock Holmes," Sherlock informed her. "Now present your case or find your way out and stop wasting my time," he snapped. An interesting case was potentially millimetres from his reach. If he wasn't going to be given the case, then he wanted her out of the flat.  
"Perhaps you are the one with amnesia," she said addressing Sherlock. "My name is Sherlock Holmes." There was a slight pause. "Now would you please explain what you're doing in my flat!"

**AN: I hope you like the concept for this story. Please write a review to let me know your thoughts. Constructive criticism is always appreciated. :)**


	2. Chapter 2

Both Sherlock and the newcomer had been staring intently at each other in silence for the last half an hour. Neither one gave any hint about what they were thinking, and left John in a state of mild confusion which would remain until one of them, most likely Sherlock, opted to provide an explanation.

"That's getting a little scary now," John commented in the hope of causing this, whatever this was, to end. The silence continued. "Sherlock?" Again, no response. Giving up John collected his coat, placing his phone in the pocket and headed out of the door. A was a few second delay before the door slammed closed and the silence finally broke.

"You're…" the woman began before trailing off into uncertainty. That was unusual for her. She was almost never uncertain about anything. "You're me, but not me," she eventually stated.  
"No," Sherlock replied, his voice taking on a disdainful tone. "You and I are two very different people. A very good impersonation, I will admit, but not enough to fool me. Now, who are you and why are you here?"  
"Once you eliminate the impossible, whatever remains, however improbable must be true," she said quietly. She then walked out the front door before Sherlock could even respond.

John returned at exactly seven o' clock in the evening to find the flat in a state of disarray. Various bits of paper were stuck all over the walls, the ceiling and areas of the floor. Even the smiley face on the wall had been completely obscured. Sherlock was sat in the middle of it all, eyes closed and obviously deep in thought. John opted to ignore the mess; he was used to all sorts of strange things happening in the flat, and this could hardly be considered strange. Not with Sherlock having a history of storing various body parts in the fridge, microwaving eyeballs and the skull above the fireplace.

"What do you think John?" Sherlock asked without even bothering to open his eyes.  
"About what?" John replied.  
"The case, John."  
"I know nothing about the case," John said slowly. "You haven't told me anything."  
"I gave you a detailed enough explanation."  
"When?"  
"About an hour ago," he informed John.  
"I wasn't it the flat an hour ago. I was working."  
"It's hardly my fault you weren't listening."

John rolled his eyes before making his way to the kitchen. He hoped that the pieces of paper he trampled on to get there weren't important. The sound of a text alert echoed through the flat. A quick glance at his phone screen confirmed that the message was from Lestrade. The message read 'Any idea who this is? They solved my case in less than five minutes!' This was then followed by a picture of the woman who was in the flat this morning.  
"Can you please explain what exactly is going on?" John exclaimed, passing Sherlock his phone and allowing him to see the message he'd just received.

"I was wondering why Lestrade hadn't been in touch," Sherlock commented, still not giving John any explanation. This just made John all the more curious.  
"What on Earth is going on, Sherlock?" Quiet echoes bounced around the flat, slowly fading into silence.  
"I don't know," Sherlock replied so quietly, that John wasn't entirely sure he heard correctly.  
"I'm sorry?"  
"I don't know!" he exclaimed. "And I really don't like not knowing…"

Sherlock typed out a quick message on John's phone and hit send. John read the text before putting his phone back into his pocket.  
'Let me know if she shows up again. -SH'


	3. Chapter 3

The scene Sherlock was greeted with was nothing if not predictable. As he entered the front door, Donovan shouted, "Freak 1 is here." Completely ignoring the remark, which was unusual for Sherlock, he strode past her, flinging open the door to Lestrade's office.  
"What's going on?" Lestrade asked, sounding just as confused as he usually did. Sherlock ignored him.  
"I was wondering when you'd show up," the woman said casually, turning to face him.  
"Impersonating me is a true waste of your potential," he replied.  
"Don't just see… observe." Sherlock frowned at that. He was a true expert at observation and deduction, and he was being told that he needed to observe.  
"Who put you up to these games?" he questioned after a few seconds. The woman didn't answer, instead handing him a neatly printed card, which read:

_When your observations have led you to the truth you seek, phone this number. -SH_

Sherlock flipped the card over to see a handwritten number printed in a familiar script. The door slammed closed a moment later.

John returned from work to find the flat in a more chaotic state than usual. Adding to the paper on the walls, ceiling and floor, was additional scraps of paper on any available surface. It looked like a tornado had made its way through the flat. Sherlock paced back and forth, trampling carelessly over the paper on the floor, reading a business card over and over again.  
"A new development on the case then?" John asked conversationally, while filling the kettle with water.  
"Obviously," Sherlock snapped. He was becoming increasingly agitated with the lack of results from his deductions which were currently leading him in circles like a dog chasing its tail. Seeing that it was unlikely there would be any sort of communication for the remainder of the day, John quickly finished making his cup of tea before heading to his room. He started his laptop and began to type a new blog post:

**_Double Deductions_**

_After finding a woman in the flat with a startling resemblance to Sherlock, it seems as though the total number of Consulting Detectives has doubled. A week ago, we found the woman in the flat who, after a short conversation, I thought may have had amnesia. She seemed to believe that the flat was hers and was confused when Sherlock disputed this fact. Curiously, there was no sign of a break in, and the front door and windows were locked, so her presence in the flat was a complete mystery._

_Since then, this woman has been solving cases, with a level of deduction that could rival Sherlock himself. At least, according to DI - who found a number of his cases solved by this mysterious individual in a very Sherlock fashion._

_Today, Sherlock saw her again. This time at Scotland Yard, where her apparently received no answers. Judging by the chaotic mess of paper in the flat at the moment, it probably won't be solved any time soon. At the moment, a business card seems to be an important clue, but what it means, or even how it fits in with any of this remain a complete mystery as Sherlock seems determined to leave me in the dark for this case._

_Hopefully, tomorrow will shed some light on the mystery that is the world's second consulting detective._

Sherlock scowled at John's most recent blog post. He was the world's only consulting detective, and to put the strange woman in the same category as him, was to destroy his 'one of a kind' status. What wasn't helping matters was that Sherlock was unable to come to a distinct conclusion about the mystery presented, and he was at times almost tempted to give up. He knew however that his curiosity would continue to linger until he solved the case.

John casually walked over to the telly, pulling the sticky notes off of the screen and placing them on the table in a neat pile. He picked up the remote before tuning in to the BBC, which was currently playing a rerun of an old 'Doctor Who' episode. 'like a parallel Earth where they've got zeppelins?' Sherlock heard from the TV speakers. Immediately after, John changed the channel to the news, which naturally was focusing on the arrival the newest London crime solver.

Sherlock, wanting to remove any possible distractions such as the noise from the telly, snatched the remote from where John had placed it, and pressed the off button.  
"I was watching that!" John informed him, stating the obvious.  
"It's not as though it was telling you anything you didn't already know," Sherlock replied, throwing himself onto the sofa. He dropped the remote to the floor.

After a short period of silence, Sherlock pulled his phone from his pocket and quickly typed in the number shown on the business card. The phone call was short and shed little light on the case that John knew so little about. After about ten seconds, Sherlock hung up, grabbing his coat and heading out the door. Not a second after the door closed, the clock chimed midnight.

**AN: Sorry I haven't updated in a while. Please let me know your thoughts on the story so far. Constructive criticism is always appreciated.**


End file.
